Intraocular ring assembly and artificial lens kit

ABSTRACT

An intraocular ring assembly and an artificial lens kit, both of which are usable for implantation in a lens capsule or capsular bag of natural eye. The intraocular ring assembly includes a first ring element having recessions therein, a second ring element, and a biasing element provided between the first and second ring elements. The artificial lens kit comprises such intraocular ring assembly and an intraocular lens to be movably supported in the recessions of the ring assembly in a coaxial relation therewith. A guide element may be provided to assist in rectilinear coaxial movement of the first and second ring elements.

This is a Division of application Ser. No. 11/377,677 filed Mar. 17,2006, now U.S. Pat. No. 7,462,193, which in turn is a Divisional ofapplication Ser. No. 10/295,856 filed Nov. 18, 2002, now U.S. Pat. No.7,037,338. The disclosure of the prior applications is herebyincorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an accommodating intraocular lens to beimplanted in a lens capsule (or a capsular bag) of human or natural eyein a surgical procedure subsequent to extracapsular cataract extraction.In particular, the invention is directed to a novel intraocular ringassembly and a novel artificial lens kit for implantation in the lenscapsule or capsular bag, which are designed to enable the eye to have anoptimal accommodation to gain near and distant visions.

2. Description of Prior Art

A human eye has a crystalline lens which is endowed with accommodation,i.e. a natural focal function in the lens to adjust its focus on anobject being moved from a far distance to a nearby distance, or viceversa, so that a human being with the eyes can keep a clear vision forthe moving object.

It is generally believed that the accommodation of human eye is based onthe following actions: When the eye gazes at an object located at a fardistance, a crystalline lens in the eye, which substantially serves asan artificial optical lens, is kept in a flattened state. Now, when theeye changes its gazing from the object at a far distance to a new objectlocated at a nearby distance, a circular ciliary muscle (a circularmuscle of ciliary body (at 50 in FIG. 21)) circumscribing thecrystalline lens is contracted to cause relaxation of zonule of Zinn(see the designation 42 in FIG. 21), because of the lens being connectedvia the zonule (plural thin fibrous tissues) with a ciliary body (at 50in FIG. 21). Such relaxation of zonule allows the crystalline lens tobecome inflated into a spherical shape, increasing its thickness, due tothe inherent elastic expansive property of the lens, whereby therefractive power of the lens is increased so as to properly adjust afocus on the object at near distance, thus attaining a clear visionthereof.

By contrast, when the eye changes its gazing from the nearby object to afar distant object, the actions are reversal: the circular ciliarymuscle mentioned above is then relaxed to cause traction of thecrystalline lens via the zonule, thereby stretching the crystalline lensoutwardly, with the result that the lens is transformed into a flattenedshape from the spherical shape, thus decreasing the refractive power ofthe lens so as to properly adjust focus on the far distant object.

The crystalline lens is normally transparent, but, for some reasons orother, the lens itself is subjected to opacification. In that case, alight entering the eye is scattered by the opacified crystalline lensbefore reaching a retina, and therefore, a precise image can hardly beformed at the retina or fundus, which results in a misted or dim vision.In most cases, this symptom is what is generally known as “cataract”.The nature of the cataract varies according to different causes, such asan age-related cataract, a congenital cataract, a diabetic cataract, atraumatic cataract, and a glass-blower's cataract due to an occupationaldisease caused by exposure to infrared rays. Recent years witness anincreased number of cataract patients.

A brief explanation will be made as to the crystalline lens. Crystallinelens is in the form of a biconvex lens and has a transparent outer thincapsular membrane with an elastic property, which covers the entirety ofan inner lens matrix. Such capsular outer membrane is what is referredto as “lens capsule”. Ophthalmologically stated, the lens capsule isdivided into a forward portion facing to a cornea (see the designation52 in FIG. 21); i.e. what is referred to as “anterior capsule”, and arearward portion facing to a vitreous (see the designation 53 in FIG.21); i.e. what is referred to as “posterior capsule”.

The boundary between those anterior and posterior capsules is theso-called “equator” which expends along the outer circumference of thelens capsule. Integrally fixed to the periphery of the lens capsulesubstantially corresponding to the equator is the zonule which connectthe crystalline lens and the ciliary body.

Typical treatment for the foregoing crystalline lens disease, or thecataract, includes an intraocular lens implantation to replace anopacified natural lens. This sort of procedure normally entails thesteps of making an incision to the anterior capsule of the lens to forma circular opening therein, then extracting an inner matrix from thelens capsule via such circular opening to leave an empty capsule or theso-called capsular bag, and thereafter, implanting an intraocular lensin that capsular bag.

Conventional intraocular lenses, however, do not provide a sufficientaccommodation since they are incapable of increasing and decreasing thethickness of the lens itself, and do not insure a precise forward andbackward movement of the lens in the direction anteriorly andposteriorly of eye. Yet, almost all of the conventional intraocularlenses are not designed to gain an optimum focus on near and distantobjects, and, in most cases, they still rely on a fixed focus, resultingin a wearer of the intraocular lenses requiring eyeglasses. As aconsequence thereof, it can be mentioned that the conventionalintraocular lenses can not work with ciliary body and zonule to asatisfactory degree, and therefore, have not yet achieved an optimumfocus on every object located at near or far distance, raising theproblem that the lens wearer can not have a satisfactory clear visionfor various objects at all ranges of distances and will encounter anyunexpected inconvenience and trouble postoperatively.

SUMMARY OF THE INVENTION

With the above-stated shortcomings in view, it is a purpose of thepresent invention to provide an intraocular ring assembly that is ofsuch a structure that allows its ideal implantation in a lens capsule orcapsular bag of natural eye, while achieving a high sensitivity tochanges in shape of the lens capsule due to contraction and relaxationof the ciliary body via the zonule, and also preventing after-cataractproblem.

In order to attain such purpose, the intraocular ring assembly inaccordance with the present invention is basically comprised of:

-   -   a first ring element having a center;    -   a second ring element having a center;    -   at least two recessions defined in said first ring element; and    -   a biasing means provided between said first ring element and        said second ring element,    -   wherein the first and second ring elements are resiliently        supported by the biasing means such that the center of the first        ring element is in a coaxial relation with the center of the        second ring element, and wherein the biasing means resiliently        urges the first and second ring elements in a direction opposite        to each other.

It is another purpose of the present invention to provide an artificiallens kit which can be effectively used for implantation in a lenscapsule or capsular bag of natural eye in order to realize a properaccommodation of the eye with a high sensitivity to changes in shape ofthe lens capsule due to contraction and relaxation of the ciliary bodyvia the zonule, while preventing after-cataract problem.

For that purpose, the artificial lens kit in accordance with the presentinvention is basically comprised of:

-   -   an intraocular lens having an optic portion and a haptic means        provided on a peripheral end of said optic portion, the haptic        means being adapted to contact an inner surface of a lens        capsule corresponding to an equator of the lens capsule; and    -   an intraocular ring assembly in which the intraocular lens is        supported in a coaxial relation therewith, which intraocular        ring assembly includes:        -   a first ring element having a center and a support means for            supporting the haptic means of the intraocular lens therein,            the first ring element having one side    -   adapted to be contacted with the anterior capsule and another        side opposite to that one side;        -   a second ring element having a center and one side adapted            to be contacted with the posterior capsule and another side            opposite to that one side; and        -   a biasing means provided between the first ring element and            the second ring element;    -   wherein the biasing means resiliently urges the first ring        element in a direction to the anterior capsule, while        resiliently urging the second ring element in a direction to the        posterior capsule.

In a first aspect of the invention, the support means may comprise atleast two support recessions defined in the first ring means, and eachof the at least two haptic portions may include a base area connectedwith the peripheral end of optic portion and is so formed as to bemovably supported in each of the at least two support recessions at apoint adjacent to the base area thereof.

In a second aspect of the invention, each of the at least two hapticportions may include a bendable means defined adjacent to the base areathereof, the bendable means being adapted to render each of the at leasttwo haptic portions bendable at that base area in a vertical directionrelative to the optic portion.

In a third aspect of the invention, the bendable means may comprise acutout formed in one side of each of the at least two haptic portions inproximity to the base area.

In a fourth aspect of the invention, a first securing means may beprovided in the first ring means, while a second securing means beprovided in the second ring means, and the biasing means be secured byand between the first and second securing means.

In a fifth aspect of the invention, the biasing means may comprise atleast two elastic elements each having a generally figure-of-eight orcircular configuration.

In a sixth aspect of the invention, each of the first and secondsecuring means may comprise at least two grooves and at least onesecuring cavity formed in each of the at least two grooves, and furthermay include at least one anchor portion formed in the biasing means, sothat the at least one anchor portion is securely engaged in the at leastone securing cavity and the biasing means is partway fitted in thegroove.

In an eighth aspect of the invention, a guide means may be providedbetween the first and second ring elements, the guide means beingadapted to assist in a rectilinear coaxial movement of the first andsecond ring elements.

In a ninth aspect of the invention, the biasing means may be integrallyand directly connected between the first and second ring elements.

In a tenth aspect of the invention, a fibronectin or fibronectin-likesubstance may be included, which is applied to a part of or asubstantially whole of said at least two haptic portions of saidintraocular lens element.

Other various features and advantages of the present invention willbecome apparent from reading of the descriptions hereinafter, withreference to the annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view showing one exemplary mode ofartificial lens kit in accordance with the present invention;

FIG. 2 is a front view of the artificial lens kit;

FIG. 3 is a side elevational view of the artificial lens kit;

FIG. 4 is a schematic perspective view of one exemplary mode of anintraocular lens to be used in the artificial lens kit or intraocularring assembly of the present invention;

FIG. 5 is a front view of the intraocular lens;

FIG. 6 is a side elevational view of the intraocular lens;

FIG. 7 is a schematic perspective view showing one exemplary mode ofintraocular ring assembly in accordance with the present invention;

FIG. 8 is a side elevational view of the intraocular ring assembly shownin the FIG. 7;

FIG. 9 is a front view of the intraocular ring assembly;

FIG. 10 is a schematic perspective of the intraocular ring assembly asviewed from the bottom side thereof;

FIG. 11 (A) is a plan view of an elastic biasing element used in theintraocular ring assembly;

FIG. 11 (B) is a top plan view of the elastic biasing element in theFIG. 11 (A);

FIG. 12 (A) is a fragmentary sectional view showing an engagementrelation between an anchor portion of the elastic biasing element and ansecuring cavity formed in the intraocular ring assembly;

FIG. 12 (B) is a fragmentary sectional view showing engagement relationsamong two anchor portions of the elastic biasing element and twosecuring cavities formed in the intraocular ring assembly;

FIG. 13 is a schematic perspective view showing an alternative exemplarymode of the intraocular ring assembly in accordance with the presentinvention;

FIG. 14 is a side elevational view of such alternative mode ofintraocular ring assembly shown in the FIG. 3;

FIG. 15 is a schematic perspective view showing another alternative modeof the intraocular ring assembly;

FIG. 16 is a fragmentary sectional view of the intraocular ring assemblyshown in the FIG. 15, which shows a coil spring provided therein;

FIG. 17 is a schematic perspective view showing still anotheralternative mode of the intraocular ring assembly;

FIG. 18 is a schematic explosive perspective view showing one exemplarymode of a guide element provided in the intraocular ring assembly, whichshows a cylindrical guide member and a guide rod;

FIG. 19 is a fragmentary sectional view which explanatorily shows actionof such one mode of guide element shown in the FIG. 18;

FIG. 20 is a schematic perspective view showing yet still anotheralternative mode of the intraocular ring assembly, which utilizes aplurality of thin plate materials as the guide element;

FIG. 21 is a partly broken sectional view showing the state where anassembled unit of the artificial lens kit is implanted in a capsular bagof natural eye;

FIG. 22 is a schematic diagram which explanatorily shows the state wherethe capsular bag becomes flattened via the assembled unit of artificiallens kit when the capsular bag is stretched by traction of ciliary bodyvia the zonule; and

FIG. 23 is a diagram which explanatorily shows the state where thecapsular bag becomes swollen into spherical form via the assembled unitof artificial lens kit when the capsular bag is released from thestretched state by relaxation of zonule.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

Referring to FIGS. 1 through 23, reference numeral 2 generallyrepresents an artificial lens kit that can be used for implantation in alens capsule or a capsular bag of a natural or human's eye within thegist and scopes of the present invention.

In particular, FIGS. 1 to 3 are illustrative of one preferred mode ofthe artificial lens kit in the present invention, which is presented forexemplary purpose only, and therefore, the invention is not limited tothe shown embodiments.

The artificial lens kit 2 is basically comprised of an intraocular lens24 and an intraocular ring assembly 4 in which the lens 24 is movablysupported. As will be described later, this artificial lens kit 2 is tobe implanted within a lens capsule of natural crystalline lens, or inmost cases, it is to be implanted within a capsular bag 34 (see FIG. 21)which is an empty lens capsule from which an inner lens matrix has beenextracted from a natural lens capsule by extracapsular cataractextraction, for instance. Of course, it is essential that a center ofthe intraocular lens 24 and a center of the ring assembly 4 should be ina coaxial relation with each other, and that their central axes becoaxial with an optical axis l of eye ball E when placing the lens unit2 in the capsular bag 34, as can be seen from FIG. 21. Hereinafter,description will be made in the case where the kit 2 is to be assembledand placed or implanted in the capsular bag 34.

FIGS. 7 to 11 (B) show one exemplary mode of the intraocular ringassembly 4. In this mode, the ring assembly 4 is composed of an anteriorring element 6, a posterior ring element 8, and a plurality of elasticbiasing elements 16 provided between the anterior and posterior ringelements 6, 8. It is should be understood, referring to FIG. 21, thatthe anterior ring element 6 is to be disposed at a side facing to theanterior capsule 36 of natural crystalline lens or capsular bag 34,whereas the posterior ring element 8 is to be disposed at a side facingto the posterior capsule 38 of the crystalline lens or capsular bag 34.Those two ring elements 6, 8 are assembled together via the elasticbiasing elements 16 in a mutually coaxial relation. Again, essentially,the centers (or central axes) of the two ring elements 6, 8 be in acoaxial relation with the optical axis l when placing the lens kit 2 inthe capsular bag 34.

Both anterior and posterior ring elements 6, 8 are depicted in thefigures to assume a perfect circular configuration, but, in general,they may be formed in any desired fashion analogous to a circle foroptimum implantation in the capsular bag 34. Both two ring elements 6and 8, a principal part of the intraocular ring assembly 4, maypreferably be formed from a soft elastic material, such as acrylic orsilicon, that can be easily and resiliently deformed. Needless tomention, an optic portion 26 of the intraocular lens 24, which is to beincorporated in the intraocular ring assembly 4, may be formed from theforegoing soft elastic material, as well. This is because, in mostcases, the recent intraocular lens implantation procedure involvesfolding or rolling an elastic intraocular lens into a small piece whichis then inserted into a capsular bag so that it resiliently unfolds intoan original lens shape therein, and, for that purpose, both intraocularlens 24 and intraocular ring assembly 4 may preferably be formed fromthe soft elastic material. However, where no soft elastic material isused, the corresponding portions of intraocular ring assembly 4 may beformed in any desired structure or shape (not shown) that permits it tobe folded or rolled and then recovered into its original shape.

Preferred dimensions of the anterior and posterior ring element 6, 8 arecommonly such that the outer diameters of those two ring elements 6, 8may be set in the ranges of from 7.0 mm to 8.0 mm, whereas the innerdiameters of the same (6, 8) be set in the ranges of from 6.0 mm to 7.0mm, and the height-wise thickness of each ring element 6 or 8, as viewedfrom the side elevation of FIG. 3 for instance, may be in the ranges offrom 1.5 mm to 2.5 mm. These parameters are found effective in designingthe two ring elements 6, 8 for implantation in an ordinary size ofcrystalline lens or capsular bag 34. Of course, this is not limitativeand the dimensions of the ring elements 6, 8 may be set as desiredinsofar as they serve the purposes of the present invention.

In the illustrated embodiment, the anterior ring element 6 is formed byfour first sectorial ring portions 6A and four second sectorial ringportions 6B in such a manner that those first and second sectorial ringportions 6A, 6B are disposed equidistant in an alternately offset way.Otherwise stated, each second sectorial ring portion 6B is recessedvertically from the adjoining two first sectorial ring portions 6A thatextends horizontally along the circumference of anterior ring element 6,thereby, in the aggregate, defining four generally “U” shaped ringportions (i.e. 6B) protruding equidistantly from the respective fourfirst sectorial ring portions 6A in a vertical direction along thecentral axis of the ring element 6 as viewed from the figures.Hereinafter, the second sectorial ring portion 6B will be referred to as“generally U-shaped ring portion 6B” for a better understanding of thepresent invention.

Each first sectorial ring portion 6A has a first end surface 6Au and asecond end surface 6Ab opposite thereto. The first end surface 6Auslopes upwardly in a gradual way (at a relatively small angle ofinclination) as it proceeds toward the center (or central axis) of theanterior ring element 6 (i.e. in a direction from the outer arcuate wallthereof to the inner arcuate wall thereof), as can be seen from FIGS. 1and 3. This end surface 6Au may be formed flat, but, such slopedformation thereof is recommended to allow the ring element 6 to besmoothly placed within the capsular bag 34 in a moderate and intimatecontact with and along the generally concave inner surfaces of thecapsular bag 34 (which serves to prevent damage to that capsular bag 34per se).

On the other hand, the second end surface 6Ab is flat, in which isformed a first securing groove 13 extending therealong in an arcuatemanner, as best seen from FIGS. 8, 9 and 10. In this regard, asindicated in FIG. 8, formed in the first sectorial ring portion 6A is aspherical securing cavity 14 at a point midway of and adjacent to thesecuring groove 13. The spherical securing cavity 14 communicates withthe groove 13 at the neck portion (N) thereof (see FIG. 12 (A)) and isadapted to snappingly receive and securely engage a spherical (ordumbbell-headed) anchor piece 18 of the elastic biasing element 16, aswill be specified later.

Designation 10 represents a support recession defined in each of thegenerally U-shaped ring portions 6B, the support recession 10 beingadapted to receive and support a haptic portion 28 of intraocular lens24 therein, as will be described.

Accordingly, it is seen that four sectorial ring portions 6A aredisposed in an equidistant spaced-apart fashion along the circumferenceof a circle, with their respective four first end surfaces 6Au laying ona same level with one another along that circumference, whereas foursupport recessions 10 are alternated with the respective four sectorialring portions 6A and thus defined in a diametrically facing relationwith one another with respect to the center of ring assembly 4.

The posterior ring element 8 is shown as being simply of a circular ringshape and having outer and inner diameters equal to those of theanterior ring element 6. In contrast to the anterior ring element 6, theposterior ring element 8 has a first flat end surface 8A and a secondsloped end surface 8B opposite thereto, wherein the second end surface8B slopes downwardly as it proceeds to the center (axis) of the anteriorring element 6 (i.e. in a direction from the outer arcuate wall thereofto the inner arcuate wall thereof), as can be seen from FIGS. 1 and 3.Of course, the second end surface 8B may be formed flat.

But, the illustrated sloped formation thereof is preferable to allowsmooth placement of the ring element 8 within the capsular bag 34 in amoderate and intimate contact with and along the generally concave innersurfaces of capsular bag 34. This will advantageously avoid damage tothe capsular bag 34. Hence, it is observed from FIG. 3 that the slopedend surfaces 6Au and 8B respectively of the anterior and posterior ringelements 6, 8 are sloped in a direction away from each other as theyproceed toward a central of both two ring elements 6, 8.

In each of the first flat end surface 8A of posterior ring element 8,four second securing grooves 12 are disposed equidistantly, such thateach of them extends therealong in an arcuate manner. As indicated inFIG. 8, a spherical securing cavity 15 is formed in the posterior ringelement 8 at a point midway of and adjacent to the securing groove 12.The spherical securing cavity 15 communicates with the groove 12 at theneck portion (N) thereof (see FIG. 12 (A)) and is adapted to snappinglyreceive and securely engage a spherical anchor piece 15 of the elasticbiasing element 16, as will be specified later. For that purpose, thespherical securing cavity 15 is slightly larger than the sphericalanchor piece 18.

As illustrated, the elastic biasing element 16 is interposed between theanterior and posterior ring elements 6, 8. With particular reference toFIGS. 11 (A) and 11 (B), the elastic biasing element 16 may be of agenerally figure-of-eight shape, for instance, which is shown to have apair of integral spherical (or dumbbell-headed) anchor pieces 18, 18formed respectively in one and another opposite distal ends thereof. Thepurpose of this biasing element 16 is to keep the anterior and posteriorring elements 6, 8 away from each other in a resilient way. In otherwords, when an assembled unit of the present artificial lens kit 2 isimplanted in a capsular bag 34 as in FIG. 21, the elastic biasingelement 16 acts to bias the anterior ring element 6 in a direction tothe anterior capsule 36, while biasing the posterior ring element 8 in adirection to the posterior capsule 38. Hence, it is to be appreciatedthat the four sloped end surfaces 6Au of anterior ring element 6 arekept in a close contact with the inner surface of anterior capsule 36,while the entire sloped end surface 8B of posterior ring element 8 iskept in a close contact with the inner surface of posterior capsule 38,whereby the capsular bag 34 is normally retained in a proper biconvexshape while being allowed to become adjustably flattened and inflatedalong the optic axis l, in substantially the same manner as a naturalcrystalline lens does. Of course, the vertical length of generallyfigure-of-eight-shaped elastic biasing element 16 between the anteriorand posterior ring elements 6, 8 may be such as to normally resilientlyinflate the capsular bag 34 into a proper biconvex shape suited forindividual patient.

As best seen from FIG. 11 (B), the entire body of biasing element 16 maybe slightly warped to assume an arcuate shape equal in curvature to thefirst and second arcuate securing grooves 13, 12 stated above, since thetwo opposite distal end portions of the biasing element 16 have to befitted in and along the respective first and second arcuate securinggrooves 13, 12. This is preferable to avoid interference with smoothcontraction and expansion of the biasing element 16 per se.

The biasing or repercussive force of the biasing element 16 may bepreset to a suitable degree, depending upon the elasticity of capsularbag 34 of individual patients' eye, or other conditions required insurgical operation.

As shown, the four figure-of-eight-shaped biasing elements 16 arearranged in equidistant manner between the anterior and posterior ringelements 6, 8 such that each of the biasing elements 16 is disposedbetween each anterior ring element sectorial ring portion 6A and thecorresponding local area of posterior ring element 8.

The shape of the elastic biasing element 16 is not limited to thefigure-of-eight mode in FIG. 11 (A), but may be of generally “O” shape,for instance, (See FIG. 13), which has a diameter equal to the verticallength of the aforementioned generally figure-of-eight-shaped biasingelement 16. In this regard, the figure-of-eight-shaped or “O” shapedbiasing element may preferably be formed from a soft elastic materialsuch as polypropylene.

As understandable from FIGS. 8 and 12 (A), fixation of the four biasingelements 16 (of figure-of-eight shape) between the anterior andposterior ring elements 6, 8 is such that two opposite arcuate distalend portions of each biasing element 16 are respectively fitted andengaged in the first and second securing grooves 13, 12, while the twospherical anchor pieces 18, 18 of each biasing element 16 are snappinglyanchored in the spherical securing cavity 14 of the anterior ringelement 6 and the spherical securing cavity 15 of the posterior ringelement 8, respectively. In this way, both two ring elements 6, 8 arecoupled together via the four biasing elements 16 against separationfrom each other, thereby forming an intraocular ring assembly 4, whereinthe biasing elements 16 themselves are prevented against dislocationfrom their respective securing points. As an alternative to suchanchoring and securing means, any other suitable coupling and fittingmembers or engagement members may be provided to securely dispose thebiasing elements 16 between the anterior and posterior ring elements 6,8.

The first and second securing grooves 12, 13 may be formed in anappropriate shape and size, depending on the configuration of theelastic biasing element 16. In the case of the illustratedfigure-of-eight mode having arcuate distal end portions, it ispreferable to form two groove extensions in the respective twoextremities of each securing groove, thereby to allow both two lateralarcuate portions of the biasing element 16 to become protrudentoutwardly and stored partway in the respective two groove extensions,when the biasing element 16 is subjected to elastic depression orcontraction. Namely, as best indicated in FIG. 8, each first securinggroove 13 may be formed with a pair of groove extensions 13A, 13A in therespective two extremities thereof, while on the other hand, each secondsecuring groove 12 be formed with a pair of groove extensions 12A, 12Ain the respective two extremities thereof. By being so formed, thebiasing elements 16 are freely contractible and expandable withoutinterference with the grooves 12, 13 along a rectilinear direction,which advantageously insures rectilinear coaxial displacement of bothanterior and posterior ring elements 6, 8. This is applicable to anyconfiguration of the elastic biasing element that has arcuate endportions, including “O” shape (similar to the integral “O” shape as inFIG. 13). Hence, when the intraocular ring assembly 4 is implanted inthe capsule bag 34, such rectilinear biasing arrangement insures toallow rectilinear movement of those two ring elements 6, 8 in a coaxialrelation with the capsular bag 34 along the optic axis l.

In this context, as indicated by the phantom lines in FIG. 11 (A) andunderstandable from FIG. 12 (B), a pair of spherical (dumbbell-headed)anchor portions 18, 18 may be formed in each of the two distal arcuateend portions of biasing element 16. And, one pair of spherical securingcavities 14 may be formed in the anterior ring element 6 (i.e. in eachsectorial ring section 6A), while another pair of spherical securingcavities 15 be formed in the posterior ring element 8 in such dimensionsas to snappingly receive and securely engage the corresponding twospherical anchor portions 18, 18. This is not limitative, but a desirednumber of such securing elements (14, 15, 18) may be provided to attaina more robust and stable structure of the intraocular ring assembly 4.

It is noted that the elastic biasing element 16, be it of thefigure-of-eight shape or of a circular shape, may be formed directly andintegrally between the anterior and posterior ring elements 6, 8,without using the aforementioned anchoring or securing means (e.g. at14, 15 and 18). In this regard, as suggested in FIGS. 13 and 14 forexample, the elastic biasing element 16 may be formed in a generally “O”shaped configuration and interposed integrally between the anterior andposterior ring elements 6, 8. In this embodiment, four generally “O”shaped elastic biasing elements 16 are arranged integrally between therespective four first sectorial ring portions 6A of anterior ringelement 6 and the flat surface BA of posterior ring element 8. That is,as shown, each of those four biasing elements 16 is at one end portionthereof integrally and continuously formed with each first sectorialring portion 6A of anterior ring element 6 and is at another end portionthereof integrally and continuously formed with the posterior ringelement flat surface 8A. Of course, the diameter of each generally “O”shaped biasing element 16 is such a degree as to normally resilientlyinflate the capsular bag 34 into a proper biconvex shape suited forindividual patient as described earlier.

Or, alternatively, as suggested in FIGS. 15 and 16, the elastic biasingelement 16 may be a coil spring. According to this particular mode, foursets of two rectilinearly extending coil springs 16 are disposed inequidistant manner between the anterior and posterior ring elements 6, 8such that the paired coil springs 16 are each disposed between eachgenerally U-shaped ring section 6B and the corresponding local area ofposterior ring element 8. Further, as best shown in FIG. 16, a firstsecuring hole 12 is formed in the end surface 8A of posterior ringelement 8 in place of the afore said first securing groove 12, whereason the other hand, a second securing hole 13 is formed in the endsurface 6Ab of each first sectorial ring portion 6A in place of theafore said second securing groove 13. Accordingly, as shown, each coilspring 16 is at its one end firmly secured in the first securing hole12, while being at its another end firmly secured in the second securinghole 13. The coil spring 16 may be formed from a suitable metallicmaterial with elastic property, for instance. Of course, the verticallength of each coil spring 16 is of such a degree as to normallyresiliently inflate the capsular bag 34 into a proper biconvex shapesuited for individual patient as described earlier.

In accordance with the present invention, a guide means 22 may beincorporated in the intraocular ring assembly 4 to assist in rectilinearcoaxial movement of the anterior and posterior ring elements 6, 8.Reference is made to FIG. 17 which depict one exemplary mode of theguide means generally indicated by the parenthetic designations (22),which is interposed between the anterior and posterior ring elements 6,8. In this particular mode, as understandable from all FIGS. 17, 18 and19, four sets of two guide means 22, 22 are arranged in equidistantmanner between the two ring elements 6, 8 such that each of the pairedguide means 22, 22 is disposed between each generally U-shaped ringportion 6B and the corresponding local area of posterior ring elementend surface 8A. As best shown in FIGS. 18 and 19, each of theillustrated guide means 22 basically comprises a guide rod member 22Aand a cylindrical guide member 22B having a through-bore 22Bh formedtherein and further includes a cylindrical cavity 6H formed in theanterior ring element 6 (i.e. in the generally U-shaped ring portion6B). As understandable from FIG. 19, the guide rod member 22A is at itsone end portion fixed in a securing hole 8H formed in the posterior ringelement 8, projecting vertically therefrom. Each of the cylindricalguide member 22B has an outer diameter generally equal to the innerdiameter of the cylindrical cavity 6H and also has a whole lengthgenerally equal to that of the cavity 6H. The cylindrical guide member22B is fixedly provided in the cylindrical cavity 6H. Another endportion of the guide rod member 22A is slidably inserted in thethrough-bore 22Bh of cylindrical guide member 22B. Accordingly, asindicated by the arrow in FIG. 18, the anterior and posterior ringelements 6, 8 are positively assisted by the guide means 22 in theirprecise coaxial rectilinear movements toward and away from each other.It is noted that this guide means 22 may be formed in any other suitableconfiguration insofar as it serves to guide both two ring elements 6, 8in the coaxial rectilinear direction. Moreover, it may be so arrangedthat a rectilinearly extending coil spring, similar to the one (16)described earlier, is secured in the cylindrical guide through-bore 2Bhand cavity 6H to apply a resilient biasing force to the guide rod member22A, thereby achieving both biasing and guiding effects collectively inone localized small area for each of plural guide means 22.

FIG. 20 shows another alternative embodiment of the guide meansgenerally indicated by the parenthetic designation (22), according towhich, the guide means may be an elastic thin plate material 48 whichhas a circular hole 48H formed centrally thereof. The elastic thin platematerial 48 per se may be formed from a thin sheet of transparentplastic material with a proper resilient bendable property. In theillustrated embodiment, a pair of outward and inward elastic thin platematerials 48A, 48B are provided. Total four sets of such paired platematerials 48A, 48B are connected between the anterior and posterior ringelements 6, 8 in such a manner that the four sets of the paired platematerials 48A, 48B are disposed at the four first sectorial ringportions 6A, respectively. As viewed from FIG. 20, each outward elasticthin plate material 48A is firmly attached at the upper region thereofto the outward arcuate lateral surface of the corresponding one of thefour first sectorial ring portions 6A of anterior ring element 6, and isalso firmly attached at the lower region thereof to the outward arcuatelateral surface of posterior ring element 8. On the other hand, eachinward elastic thin plate material 48B is, at the upper, region thereof,firmly attached to the inward arcuate lateral surface of correspondingone of the four first sectorial ring portions 6A, while being, at thelower region thereof, firmly attached to the inward arcuate lateralsurface of posterior ring element 8. The provision of the holes 48H iseffective in allowing the two plate materials 48A and 48B to be easilyand smoothly bendable outwardly in a direction away from each other, andalso insuring smooth flow of air and aqueous humor between the pairedplate material 48A, 48B.

Reference being now made to FIGS. 4, 5 and 6, there is illustrated onepreferred embodiment of the intraocular lens, as generally designated by24, which is to be supported in the above-described intraocular ringassembly 4. The intraocular lens 24 is basically comprised of an opticportion 26 and a pair of haptic portions 28, 28. As shown, the optic,portion 26 is of a generally biconvex lens configuration having acircumferential end, and the two haptic portions 28, 28 are integrallyconnected with the circumferential end of optic portion 26, projectingoutwardly therefrom in a diametrically opposed direction relative to thecenter of the optic portion 26. Both optic and haptic portions 26, 28may preferably be formed from a soft elastic material, such as acrylicor silicon. But, this is not limitative and any other suitable materialmay be used to form them, taking into account the conditions andrequirements in implanting the lens 24 in a patient's eye. Also, theoptic and haptic portions 26, 28 should not necessarily be of a samematerial, but may each be of a different proper material. It is notedthat the intraocular lens 24 may be of any normally available type thatcan be mounted in the intraocular ring assembly 4 and has the bendablehaptic portions 28 which will be described later. With regard to theoptic portion 26, it is not limited to the illustrated one, but may beformed in any suitable lens configuration having a proper thickness soas to attain an optimal refractive power on the basis of a diagnosticdata on individual patient's eyes.

The illustrated two haptic portions 28 are each of a generally “T” shapewhich basically comprises: a base portion 28B integrally connected withthe circumferential end of optic portion 26; a curved distal end 28E;and a generally rectilinear body portion 28A defined between the baseportion 28B and curved distal end 28E, wherein it is seen that the bodyportion 28A has a divergently widened region near to the distal end 28E.Preferably, a generally triangular or sector-shaped hole 28H is formedin such divergently Widened region of the body portion 28A in theproximity of the curved distal end 28E. Also, preferably, the curveddistal end 28E is so formed to extend a certain distance along thecircumference of a circle whose center is at the center of the opticportion 26. With this structure, both two end portions of the hapticportion 28 are provided with a proper elasticity to render themselvesresiliently deformable according to different shape and size of capsularbag 34, so that the whole intraocular lens 24 can be smoothly set inposition and retained within a different capsular bag 34 of differentpatient's eye. In this respect, preferably, the whole size of the twohaptic portions 28 is slightly larger than the diameter of capsular bag34 to attain a positive resilient attachment of the former (28) to aninside of the latter (34). Moreover, due to its circumferentialelongation, each curved distal end 28E increases an area for contactwith and along the inner surface of capsular bag 34 corresponding to theequator 40 thereof. This allows the entirety of intraocular lens element24 to be adjustably and stably fitted in any different diameter ofcapsular bag 34, and also makes the elastic action of both two hapticportions 28 more sensitive to a contour change of the capsular bag 34being caused by the contraction and relaxation of zonule (at 42 in FIG.21).

As can be seen from FIGS. 4 to 6, each haptic portion 28 has a bendablearea 28F defined at a point adjacent to the base portion 28B thereof, sothat the haptic portion 28 per se may be resiliently bended or folded invertical direction relative to the optic portion 26. To facilitate theease of such bending action, a bendable means is provided in proximityto the base portion 28B. As such bendable means, for instance, atransverse cutout 30 is formed in one side of that bendable area 28Fadjacent to the base portion 28B in such a fashion as to assume agenerally inverted-V-shaped cross-section extending transversely of thehaptic portion 28. Accordingly, it is to be appreciated that, when bothtwo haptic portions 28 are pressed toward each other in a directioninwardly of the optic portion 26, they are quickly bended at theirrespective cutouts 30 in one direction (i.e. a direction toward a sidewhere those particular cutouts 30 are situated) relative to the opticportion 26, which in turn causes that optic portion 26 to displace inthe same direction as that one direction (as can be seen from FIG. 23)Conversely, when the two haptic portions 28 are pulled outwardly fromsuch bended state in a direction away from each other, they are extendedoutwardly on the same rectilinear horizontal line from the optic portion24 (as can be seen from FIG. 22). It is noted that the cutout 30 is justone example of bendable means for facilitating the ease with which thebendable area 28F of haptic portion 28 is bended to cause thedisplacement of optic portion 26, and such bendable means may beembodied in any other suitable manner, including hinges or the like.

A reinforcement core element 32 is preferably embedded in therectilinear body portion 28A of haptic portion 28. Provision of suchcore element 32 effectively serves to reinforce the haptic portion 28and prevent the same from being bent together with the above-statedbending action of bendable area 28F. This is also effective intransmitting most of force applied to the haptic portion 28 directly tothe cutout 30, thereby inducing more smooth bending action of the hapticportion 28 relative to the cutout 30. The core element 32 is preferablyformed from such a rigid material as a hard plastic or metallicmaterial. The artificial lens kit 2 may preferably include a fibronectinor fibronectin-like substance. Namely, it is preferable to apply anappropriate amount of suitable fibronectin or fibronectin-like substanceto the haptic portions 28 in advance, so that, in practical surgicaloperation to place the intraocular lens element 24 in the capsular bag34, both two haptic portions 28 may be positively adhered via thefibronectin or fibronectin-like substance to and along the inner surfaceregions of capsular bag 34 corresponding to the equator 40 thereof,wherein the fibronectin or fibronectin-like substance induces abiological fibrous adhesion of the haptic portion 28 to such equatorregions of capsular bag 34. Here, the term, “fibronectin-like substance”is defined as a substance containing a fibronectin, afibronectin-related substance, or any other substance exhibiting thesame fibrous adhesion effect as the fibronectins. Referring to FIG. 2,as indicated by the character Fb, a suitable fibronectin orfibronectin-like substance may be applied to the partial end region ofeach haptic portion 28. Or, alternatively, as indicated by the characterFb′, the fibronectin or fibronectin-like substance may be applied to asubstantially whole of each haptic portion 28. Whether the fibronectin(or fibronectin-like substance) should be applied to the partial endregion of haptic portion 28 or applied to a substantially whole of thesame is dependent upon the conditions and dimensions of patient's lenscapsule in order to insure an optimum adhesion of the haptic portion 28to the capsular bag equator region (at 40).

In accordance with the present invention, the above-describedintraocular ring assembly 4 and intraocular lens 24 constitute oneartificial lens kit 2 usable for implantation in the capsular bag 34. Inthe shown embodiment, the two haptic portions 28 may be set in place inthe corresponding selected two of the four support recessions 10 of theintraocular ring assembly 4. Of course, while not shown, it isoptionally possible to define only two support recessions 10 in the ringassembly 4 so as to receive and support the two haptic portions 28,respectively. But, the illustrated formation of four equidistant supportrecessions 10 is superior to such formation of only two supportrecessions 10. This is because, when putting together the lens 24 andring assembly 4 within the capsular bag 34, it is easier and quicker todrop and set the two haptic portions 28 of the lens 24 in thecorresponding two of the four recessions 10 than in the only tworespective recessions 10, due to the fact that, in the case of such fourrecessions 10, the distance between the adjacent two recessions 10 isquite small and therefore requires a less amount of rotation of the lens24 upon the ring assembly 4 to drop and set the two haptic portions 28in selected two of the four recessions 10, respectively. However, thenumber and shape of the support recessions 10 are not limitative and maybe varied, depending on the configuration of haptic portions 28 to bereceived therein.

In this context, a brief description will be made of an after cataract.In the case of extracapsular cataract extraction procedure, it is with ahigh frequency that an opacification will occur along the capsular bag34 postoperatively and the opacification may progress on to a pupilregion of the eye (i.e. a point adjacent to the center of capsular bag34), which may result in a decreased visual acuity. This symptom is whatis called “after-cataract”. Such decreased visual acuity due to theafter-cataract is a critical problem among ophthalmologists, but, thereis no effective measure to prevent the after-cataract.

The after-cataract can be classified into the following two typicalcases: “fibrous opacification” and “Elschnig's pearls”. The fibrousopacification (or fibrosis) is a state where the posterior capsule areaof capsular bag 34 becomes white and cloudy due to the production ofextracellular matrix such as collagen. In other words, after cataractoperation, a part of the epithelial cells of natural crystalline lens istransformed into myofibroblast-like cells which in turn produce a greatamount of the extracellular matrix composed of fibrous tissues(including “type I” collagen and “type II” collagen). Thus, theextracellular matrix so produced causes the fibrous opacification(fibrosis) in a part of posterior capsule 38. More specifically stated,in cataract operation, an incision is first made to the anterior capsuleof lens 36 in a circular manner relative to the center thereof (i.e.anterior capsulotomy), the anterior capsule 36 having a lens epithelialcell thereon (the lens epithelial cell exists only in the anteriorcapsule). Hence, defined in the anterior capsule 36 is a circular edge(see 44E in FIG. 21) which is indeed a place where the lens epithelialcell will be transformed into myofibroblast-like cell. In the earlypostoperative stage, since the anterior capsule 36 is slack and foldedinwardly thereof due to the circular incision, a whole of the anteriorcapsule 36 starts to be gently adhered by fibrin and other factors tothe posterior capsule 38. In most cases, such adhesion occurs in theequator region of capsular bag 34 and develops toward the circular edge44E of anterior capsule 36, after which, under the influence of sodeveloped adhesion, the lens epithelial cell remnant in the anteriorcapsule 36 proliferates while being transformed into myofibroblast-likecell, and also, some other cells are subjected to transdifferentiation.These transformed and transdifferentiated cells produce a great amountof fibrous extracellular matrices which tend to strongly adhere thatcircular edge 44E to and along the capsular bag equator region at 40.Thus, fibrous opacification (or fibrosis) is generated from such adheredregion or fibrous extracellular matrices and develops therefromexcessively toward the pupil area or a center of iris (at 51 in FIG.21), resulting in a decreased visual acuity of the patient's eyes.

On the other hand, upon such adhesion of the entire circular edge 44E ofanterior capsule 36 to the inner surfaces of posterior capsule 38, anannular closed space is defined between the anterior and posteriorcapsules 36, 38 in a doughnut-like fashion. In the annular closed space,a new natural crystalline lens is gradually formed. The majorconstituent tissue of the new natural crystalline lens comprises lensfiber cells regenerated in the space. When the natural crystalline lensoccupies that closed space, the plural lens fiber cells thereof keep onproliferating and passing through the adhesion area at which theanterior capsule annular edges 44E are adhered to the posterior capsule38. At last, the lens fiber cells reach a humor chamber outside theposterior capsule 38 and are exposed to aqueous humor in the anteriorchamber. Given a certain influence of the aqueous humor, the lens fibercells become swollen into a plurality of the so-called “Elschnig'spearls”, another case of the after-cataract. The Elschnig's pearlsscatter a light entering the eye and decrease the visual acuity.

To prevent both foregoing two types of after-cataract, it is importantto avoid the adhesion of the anterior capsule edge 44E to the posteriorcapsule 38. In accordance with the present invention, the intraocularring assembly 4 works effectively for that purpose. Namely, shortlyafter completion of the anterior capsulotomy, the ring assembly 4 isinserted through the circular opening (see 44 in FIG. 21) and placed inthe inside of the capsular bag 34, whereupon the anterior and posteriorcapsules 36, 38 are biasingly separated from each other by therespective anterior and posterior ring elements 6, 8, due to the elasticbiasing elements 16, thereby keeping the circular opening 44 and itsannular edge 44E away from the anterior capsule 36, as understandablefrom FIG. 21. Thus, there is no such biological adhesion problem statedabove between the anterior and posterior capsules 36, 38. Moreover, thefibrous opacification, if any, would occur within a very limited smallregion around the annular edge 44E and thus will never develop therefromto the anterior capsule 38. The intraocular ring assembly 4 of thepresent invention, therefore, insures to prevent the decreased visualacuity due to the fibrous opacification.

In this connection, it is preferable to form grooves and holes in theanterior ring element 6 for the purpose of allowing free circulation ofaqueous humor, though not shown. In view of an intimate contact betweenthe anterior ring element 6 and the corresponding area of inner surfaceof the anterior capsule 36, those grooves and holes will allow a properamount of the aqueous humor to be flowed between the ring 6 and anteriorcapsule 36, thereby eliminating a possible increase oftransdifferentiated cells and other factors which may produce a greatamount of fibrous extracellular matrixes. In that case, therefore, anybiological adhesion will not cause between the circular edge 44E andboth anterior and posterior capsules 36, 38, and neither will be formedany closed space in the capsular bag 34, the closed space being a placeallowing regeneration of lens fibrous cells and incidental formation ofElschnig's pearls therein as mentioned above. Such provision of groovesand holes is a matter of choice to effectively prevent a lowered visualacuity due to the Eischnig's pearls.

Now, reference being made to FIGS. 21 to 23, a specific description willbe made of how the artificial lens kit 4 is used for implantation in thecapsular bag 34 and how it works for accommodation of the eye therein.

FIG. 21 depicts the state where the artificial lens kit 4 is used forimplantation in a crystalline lens of human eye. In a human eye E, acrystalline lens or a capsular bag 34 is inherently connected at itsentire equator region 40 with the zonule 42 which are in turn inherentlyconnected with the circular ciliary muscle 50. Designations 51 and 52denote a cornea and an iris, respectively. Designation 53 denotes avitreous body.

At first, an anterior capsulotomy is effected by making a circularincision to the anterior capsule 36 of crystalline lens so as to form acircular opening 44 therein. An inner matrix is then extracted from thecrystalline lens via the opening 44 to leave an empty lens capsule or acapsular bag 34. Provided now is one artificial lens kit 2 of thepresent invention, which is a normally available mode complete with bothintraocular ring assembly 34 and intraocular lens 24. First, theintraocular ring assembly 34 is taken from such kit 2 and insertedthrough the opening 44 into the inside of capsular bag 34. And then, theintraocular lens 24 with a pair of bendable haptic portions 28, takenalso from the kit 2, is likewise inserted through the opening 44 intothe capsular bag 34 and placed upon the ring assembly 34 therewithin. Atthis point, a surgeon should rotate the intraocular lens 24 generallycoaxially of the ring assembly 34 so that the two haptic portions 28 ofthe former are respectively dropped and received in a selecteddiametrically-opposing pair of support recessions 10 of the latter.Thereafter, due to the fibronectin or fibronectin-like substance appliedto a part of or a substantially whole of each haptic portion 28 asindicated by Fb or Fb′ in FIG. 2, both two haptic portions 28 are firmlyand integrally adhered, as indicated at F, to the inner surface regionsof capsular bag 34 corresponding to the equator region 40 thereof underthe biological adhesive effect induced by the fibronectin orfibronectin-like substance.

In this way, both intraocular lens 24 and ring assembly 4 are assembledand retained in position within the capsular bag 34 in a coaxialrelation with each other, wherein their axes extend along the optic axisl, as can be seen from FIG. 21.

Referring now to FIGS. 22 and 23, with the thus assembled unit ofintraocular ring assembly 4 and lens 24 in the capsular bag 34, theanterior ring element 6 is urged by the elastic biasing element 16 intocontact with the inner surface of anterior capsule 36, whilesimultaneously, the posterior ring element 8 is urged by the biasingelement 16 into contact with the inner surface of posterior capsule 38.More specifically, the two sloped end faces 6Au, 8B respectively of theposterior and anterior ring elements 6, 8 are biasingly kept in a fitcontact with and along the generally concave inner surfaces of posteriorand anterior capsules 36, 38. With this structure of ring assembly 4,the capsular bag 34 is retained in a proper biconvex shape while beingallowed to be flattened and inflated in a coaxial relation with theoptic axis l, which positively keeps the anterior capsule circular edge44E away from the posterior capsule 8, as described above. At the sametime, both two arcuate ends 28E respectively of the two haptic portions28 are securely contacted with and along the inner surface regions ofcapsular bag 34 corresponding to the equator region 40 thereof.

In FIG. 22, upon traction of the capsular bag 34 via the zonule 42 dueto relaxation of the ciliary body 50, the capsular bag equator 40connected with the zonule 42 is drawn outwardly and radially asindicated by the arrows {circle around (1)}, which in turn pulls thehaptic portions 28 of lens 24 in diametrically opposite directions.Consequently, as understandable from another arrows, the anterior andposterior capsules 36, 38 are displaced toward each other, whereby thecapsular bag 34 is flattened, hence reducing the distance between theanterior and posterior ring elements 6, 8, while resiliently depressingthe elastic biasing elements 16, with the result that the two hapticportions 28 received in the support recessions 10 of anterior ringelement 6 are extended outwardly and brought to substantially the sameline with the equator region 40 (i.e. on substantially rectilinear line)as those two particular haptic portions 28 are articulated relative totheir respective two bendable portions 28F or the respective two cutouts30. Simultaneous therewith, the optic portion 26 is rectilinearly movedalong the optic axis l in a direction posteriorly of the capsular bag 34(i.e. toward the posterior capsule 38) and located at a point generallylevel with the equator 40. Accordingly, the eye E has made a properaccommodation to adjust its focus on a far or distant object.

Conversely, referring to FIG. 23, when the zonule 42 is now relaxed asindicated by {circle around (2)} (due to contraction of the ciliary body50), the capsular bag 34, which has been stretched outwardly at theequator region 40 thereof as described above, now tends to contracttoward its center, reducing the diameter of its equator 40. At thismoment, the outwardly biasing force of elastic biasing elements 16 isreleased from the depressed state so as to urge the anterior andposterior ring elements 6, 8 in a direction away from each other,thereby helping to positively contract the capsular bag 34 into a properspherical shape. Consequently, as indicated by another arrows, both twohaptic portions 28 are bent in one direction toward each other withrespect to their respective bendable portions 28F or cutouts 30 and thusdisplaced nearer to the center of optic portion 26. This simultaneouslycauses the optic portion 26 to move rectilinearly along the optic axis lto a point anteriorly of the capsular bag 34 (i.e. toward the anteriorcapsule 36). Thus, the eye E has made a proper accommodation to adjustits focus on a near object.

In this connection, preferably, provision of the previously describedguide means 22 in the intraocular ring assembly 4 will assist in preciserectilinear movement of the lens 24 along the optical axis l.

In the foregoing ways, the thus-implanted unit of intraocular lens 24and ring assembly 4 in the eye E works finely and precisely in responseto contraction and relaxation of the zonule 42 as well as to change inshape of whole capsular bag 34, whereby the optic portion 26 is quicklysubjected to a proper variation in refractive power and smoothly changesits focus upon a near or distant object being viewed.

It should be understood that the present invention is not limited to theillustrated embodiments, but any other modifications, replacements andadditions may be applied thereto without departing from the scopes ofthe appended claims.

EFFECTS OF THE INVENTION

From the descriptions above, it is appreciated that the intraocular ringassembly 4 and the artificial lens kit 2 in accordance with the presentinvention has the following effects and advantages:

(1) The intraocular ring assembly 4 in characterized by comprising ananterior ring element 6, a posterior ring element 8, an elastic biasingelement 16 securely connected between those two ring elements 6, 8, andsupport portions 10, The artificial lens kit 2 comprises a novelcombination of such intraocular ring assembly 4 and an intraocular lens24, such that the two bendable haptic portions 28 of intraocular lens 24is to be movably received in the support portions 10 of the intraocularring assembly 4, respectively, when implanting an assembled unit of thering assembly 4 and lens 24 in the lens capsule or capsular bag 34.

(2) The assembled unit of intraocular ring assembly 4 and lens 24 isfitted in substantially a whole inner area of the capsular bag 34 andprovides a far increased sensitivity to every change in shape of thecapsular bag 34 which is caused by contraction and relaxation of theciliary body 50 via the zonule 42 adjoining the capsular bag 34, whileserving to not only retain an optimum shape of the capsular bag 34, butalso preventing after-cataracts as elaborated earlier. Further, theoptical portion 26 is precisely moved anteriorly and posteriorly alongthe optic axis l responsive to change in shape of the capsular bag 34.Thus, even after extracapsular cataract extraction, the eye, in whichthis assembled unit of intraocular ring assembly 4 and lens 24 isimplanted, can not only accommodate itself to different distances asnaturally and smoothly as a natural crystalline lens does beforecataract, but also is prevented from after-cataracts.

(3). In addition, the guide means 22 insures a precise rectilinearmovement of both anterior and posterior ring elements 6, 8, which makespositive the rectilinear displacement of the intraocular lens 24coaxially of the capsular bag 34 along the optic axis l, therebyrealizing an optimum accommodation of the eye (s) without defocusingproblem.

1. An artificial lens kit for implantation in a lens capsule of naturaleye in which the lens capsule has an equator, comprising: an intraocularlens having an optic portion and a haptic means provided on a peripheralend of said optic portion; said haptic means being adapted to contact aninner surface region of said lens capsule corresponding to said equator;an intraocular ring assembly in which said intraocular lens is supportedin a coaxial relation therewith, said intraocular ring assemblyincluding: a first ring element having a center and a support means forsupporting said haptic means of said intraocular lens therein; a secondring element having a center; a biasing means provided between saidfirst ring element and said second ring element, wherein said first andsecond ring elements are resiliently urged by said biasing means in adirection opposite to each other, such that the center of said firstring element is in a coaxial relation with the center of said secondring element; and wherein a first securing means is provided betweensaid first ring element and said biasing means, whereas a secondsecuring means is provided between said second ring element and saidbiasing means, and wherein said biasing means is secured between saidfirst and second ring elements via said first and second securing means,wherein said biasing means comprises at least two elastic elements eachhaving a configuration of generally figure-of-eight, and wherein each ofsaid at least two elastic elements is secured, at one end portionthereof, to said first ring element by said first securing means, whilebeing secured, at another end portion thereof, in said second ringelement by said second securing means, wherein said first securing meanscomprises: at least two first grooves formed in said first ring element;and at least one first securing cavity formed in each of said at leasttwo first grooves, said first securing means further including at leastone first anchor portion formed in each of said at least two elasticelements; wherein said second securing means comprises; at least twosecond grooves formed in said second ring element; and at least onesecond securing cavity formed in each of said at least two secondgrooves, said second securing means further including at least onesecond anchor portion formed in each of said at least two elasticelements, and wherein said at least one first anchor portion and said atleast one second anchor portion are securely engaged in said at leastone first securing cavity and said at least one second securing cavity,respectively, while said at least two elastic elements are partwayfitted in said at least two first grooves, respectively, and are alsopartway fitted in said at least two second grooves, respectively.
 2. Theintraocular ring assembly according to claim 1, wherein a grooveextension is formed in each of said at least two first grooves, whereasanother groove extension is formed in each of said at least two secondgrooves, thereby allowing each of said at least two elastic elements tobe freely contractible and expandable in a rectilinear direction withoutinterference with said at least two first grooves and said at least twosecond grooves.